Use of In-Clinic Diagnostic Kits for the Detection of Seropositivity to Leishmania infantum and Other Major Vector-Borne Pathogens in Healthy Dogs

Canine Vector-Borne Diseases (CVBDs) are widespread in Europe and enzootic in many other countries. Though severe illnesses may occur, dogs living in enzootic areas often show vague or no clinical signs of CVBDs. Undiagnosed infections/co-infections in subclinically infected animals favor the spread of CVBDs and increase the risk of transmission to other animals and, in some cases, humans. This study has evaluated the exposure of dogs living in key enzootic countries, i.e., Italy and Greece, to major CVBDs via the use of in-clinic diagnostic kits. Overall, 300 privately owned dogs without/with single mild clinical signs living in different regions of Italy (n. 150) and Greece (n. 150) were included in the study. As part of a clinical examination, a blood sample was collected from each dog and subjected to two serological rapid tests, i.e., the SNAP(®) 4Dx(®)Plus (IDEXX Laboratories Inc.) for the detection of antibodies against Ehrlichia spp., Anaplasma spp., Borrelia burgdorferi s.l. and Dirofilaria immitis antigen and the SNAP(®) Leishmania (IDEXX Laboratories Inc.) for the detection of antibodies against Leishmania infantum. In all, 51 dogs (17%; 95% CI 12.9–21.7) were seropositive to at least 1 pathogen, i.e., 4 in Italy (2.7%; 95% CI 1.4–13.1) and 47 in Greece (31.3%; 95% CI 24–39.4). Dirofilaria immitis antigens were found in 39 dogs (13%; 95% CI 9.4–17.3), while antibodies against Ehrlichia, Anaplasma and Leishmania were detected in 25 (8.3%; 95% CI 5.5–12.1), 8 (2.7%; 95% CI 1.2–5.2) and 5 (1.7%; 95% CI 0.5–3.8) dogs, respectively. None of the dogs tested seropositive for B. burgdorferi s.l. Statistical analyses were performed to evaluate associations between exposure to CVBDs and possible risk factors. The present results indicate that dogs living in enzootic areas may be seropositive for one or more CVBDs in absence of clinical signs. Rapid kits are among first line tools for the detection of CVBDs in clinical settings, as they are cost-effective, straightforward and quick to use. Also, in-clinic tests used herein allowed detection of co-exposure to CVBDs investigated.